Matochik J A, Barfield R J, Nyby J
Department of Biological Sciences, Rutgers University, New Brunswick, New Jersey 08903.
Horm Behav. 1992 Dec;26(4):545-55. doi: 10.1016/0018-506x(92)90021-m.
Two experiments examined the role of the steroid hormones, estradiol (E2), progesterone (P), and testosterone (T), in activating scent marking and 50-kHz ultrasonic vocalizations in ovariectomized Long-Evans rats in response to a devocalized male rat. In Experiment 1, females received, in a counterbalanced order, a series of six hormone treatments consisting of two injections (48-54 and 4 hr before behavioral tests). The six treatments were 8 micrograms E2 followed by 500 micrograms P or oil, 2 micrograms E2 followed by 500 micrograms P or oil, and oil followed by 500 micrograms P or oil. Injections of either the high or low dose of E2 followed by P resulted in high levels of vocalizations. Neither E2 by itself or P by itself were very effective. Surprisingly, none of the hormone treatments were effective in activating marking above the level seen when the females received control injections of oil. Four other hormone treatments were examined in Experiment 2: daily injections of 500 micrograms T, daily injections of 50 micrograms E2, implantation of silastic capsules of E2 (5% E2, 5 mm length) followed by 500-micrograms P injections before behavioral tests, and implantation of silastic capsules of E2 followed by oil injections. Animals receiving E2 by silastic capsule followed by P injection displayed the highest levels of marking and vocalizations across the five weekly tests. These results suggest that while E2 and P synergize for the display of female-typical behaviors similar to the hormonal regulation of lordosis, the mechanism of E2 action may be different for the two signaling behaviors. Scent marking appears to be responsive to the tonic levels of E2 released from silastic capsules.
两项实验研究了类固醇激素雌二醇（E2）、孕酮（P）和睾酮（T）在激活去卵巢的Long-Evans大鼠的气味标记和50千赫兹超声波发声方面的作用，这些大鼠对一只去声带的雄性大鼠做出反应。在实验1中，雌性大鼠以平衡顺序接受一系列六种激素处理，包括两次注射（行为测试前48 - 54小时和4小时）。这六种处理分别是8微克E2后接500微克P或油，2微克E2后接500微克P或油，以及油后接500微克P或油。注射高剂量或低剂量的E2后接P会导致高水平的发声。单独的E2或单独的P都不是很有效。令人惊讶的是，没有一种激素处理在激活标记方面比雌性大鼠接受对照油注射时更有效。在实验2中研究了另外四种激素处理：每天注射500微克T，每天注射50微克E2，在行为测试前植入含5% E2、长5毫米的E2硅橡胶胶囊后注射500微克P，以及植入E2硅橡胶胶囊后注射油。在为期五周的测试中，接受E2硅橡胶胶囊后接P注射的动物表现出最高水平的标记和发声。这些结果表明，虽然E2和P协同作用以表现出类似于脊柱前凸激素调节的雌性典型行为，但E2对两种信号行为的作用机制可能不同。气味标记似乎对从硅橡胶胶囊释放的E2的持续水平有反应。
